1. Technical Field
The present invention generally relates to motor vehicles. More particularly, the present invention relates to a method and apparatus for transferring rear shoulder belt loads to a vehicle frame.
2. Discussion
In addition to housing passengers and supporting a vehicle's systems, a vehicle's body shell performs four essential structural functions: suspension support, noise attenuation, shake control, and crash energy management. One aspect of the vehicle structure that can affect these characteristics and which can be designed to optimize them is the "C" pillar design. Typically an automotive body has several "pillars", commonly referred to as the "A", "B", and "C" pillars. Some vehicles also have a "D" pillar. These pillars come in pairs, one on each side of the vehicle body. The A-pillar is the front pillar that supports the windshield and front of the roof. The B-pillar is the side post that connects the roof to the rocker panel. The C-pillar supports the back window and the rear portion of the car's roof. In some vehicles, such as sport utilities vehicles, there is also a D-pillar that supports the rearmost section of the roof.
Known C-pillar joint constructions rely on single horizontal fore-aft attachments of the C-pillar to the vehicle underbody. These designs are prone to "parallelogramming", which occurs when the aperture of the rear window, the aperture being the circumferential periphery of the window, causes a bending or flexing of the C-pillar about the horizontal fore/aft attachment line to the body. This flexing reduces body torsional stiffness and allows parallelogramming movement/deflection of the rear window aperture, resulting in increased backlight to body squeak. Indeed, in known constructions the base of the C-pillar almost becomes a flex concentration point for lateral inputs, the horizontal weld orientation serving as a hinge or fulcrum line. To counter this tendency, substantial reinforcements or "gussets" typically are required in such designs, requiring extra weight and assembly time.